Antibody-drug conjugates (ADCs) combine the high specificity of monoclonal antibodies with the high anti-tumor activity of small molecular cytotoxic payloads. In 2013, the human epidermal growth factor receptor 2 (HER2)-targeted ADC ado-trastuzumab emtansine (T-DM1) entered the treatment arsenal for patients with metastatic breast cancer (BC), making it the first ADC to be approved for the treatment of a solid tumor. The pace of ADC development for solid tumors has since increased dramatically, with currently more than 100 ADCs being investigated in clinical trials. Specifically in breast cancer, there are now 3 EMA-approved ADCs: T-DM1, trastuzumab deruxtecan (T-DXd) and sacituzumab govitecan (SG). This article will briefly touch upon the key components and mode of action of ADCs after which the clinical experience with the EMA-approved ADCs in breast cancer will be discussed.
